European Patent No. 253 717 discloses ophthalmic formulations containing combinations of specific beta adrenergic receptor antagonists (beta-blockers) and pilocarpine for the treatment of elevated intraocular pressure in patients refractory to treatment with beta-blockers alone. The patent discloses a beta-blocker concentration of 0.5 to 1.0 weight/volume percent (wt./v.%) and a pilocarpine concentration of 2 to 4 wt./v.%. The claimed formulation is made by combining lyophilized pilocarpine hydrochloride and a solution of an ophthalmic beta-blocker.
A product known as Normoglaucon has been sold in Germany. The product contains 2% pilocarpine and 0.1% metipranolol.
U.S. Pat. No. 4,474,751 discloses an ophthalmic drug delivery system using selected polymers which use the body temperature and pH to induce liquid to gel transition of the polymers. The patent discloses an extensive list of drugs which can be administered by the system, including a combination of timolol or R-timolol with pilocarpine. The specific examples do not describe any formulations of any drug combinations.